noun
defect
A fault or imperfection; as a verb, to abandon one side for another.
Where it comes from
Defect ordinarily means a fault or imperfection; as a verb, to abandon one side for another. The noun and verb defect both descend from Latin deficere, to be lacking, fail, or abandon. Its past participle defectus could describe failure, absence, weakness, or falling away. One branch made a defect something that fails to meet what is needed. Another made to defect the act of failing a cause or falling away from one's side.
How the meaning developed
English marks the split in speech: the noun stresses the first syllable, the verb usually the second.
Sources
Definitions adapted from Open English WordNet where applicable. License and attribution. Word-history text comes from Lexifour’s sourced social research; pages are assembled automatically, not individually fact-checked on every update.
Updated 2026-10-05. Report a correction.